# Why is the number '4' so prominent in the Death Note?

In Death Note (TV Series 2006–2007), there is a pattern in a lot of the numeric references in the rules of the Death Note, where they relate to the number 4 in some way:

If the cause of death is written within the next 40 seconds of writing the person's name, it will happen.

After writing the cause of death, details of the death should be written in the next 6 minutes and 40 seconds [= 400 seconds total].

If a human uses the note, a god of death usually appears in front of him/her within 39 days [under 40 days] after he/she uses the note.

The Death Note will be rendered useless if the victim's name is misspelled four times.

If you lose the Death Note or have it stolen, you will lose its ownership unless you retrieve it within 490 days [a year and 4 months].

If writing the same name on more than two Death Notes is completed within a .6 seconds [0.4 seconds away from 1], it is regarded as simultaneous; the Death Note will not take effect and the individual written will not die.

Those with the eye power of the god of death will have the eyesight of over 3.6 [0.4 away from 4] in the human measurement, regardless of their original eyesight.
"Rules of the Death Note", Death Note Wiki

There are a few instances where other significant numbers ("magical number" 3, and "devil number" 6) are used, but none are quite as prevalent as 4.

Is this prevalent pattern a coincidence, or is there some significance to the number 4 that would be relevant in Death Note?

• A year and four months is 16 (4 x 4) months. Sep 4, 2017 at 12:46
• Mathematically, it's called Fourier Transformation Sep 5, 2017 at 8:51
• @Ooker I was all set to point out to you that you'd accidentally commented on the wrong question, then I followed the link... Sep 5, 2017 at 9:46

Because apparently, Four is Death. from the TV Tropes page of the same name:

In most Chinese languages and languages that borrow words from it, the words for "four" (四) and "death" (死) are written differently but pronounced similarly (somewhat like "sì" in Mandarin, "sei" in Cantonese, "shi" in Sino-Japanese, "tư" in Sino-Vietnamese, and "sa" in Sino-Korean). As a cultural trope, East Asian works of media tend to treat the number in much the way Western writers treat the number 13 (a number that Arabian and European culture consider Magical, and usually in a bad way).

• Upvote for the TV tropes page, as it lists Death Note and gave some more references that I hadn't picked up on. For example, `Light's given name is spelt as "moon" (月)` apparently this has four strokes, cursing him with an unlucky/deadly curse from birth. Sep 4, 2017 at 12:12
• Fun, but not quite related fact: Garmin skipped their 4th version of the fenix, because of this pronunciation similarity. Sep 4, 2017 at 14:19
• Noticeable if you are somewhere where enough people have tetraphobia that buildings skip the numeral 4 when labelling floors. Really noticeable if you are somewhere where there are also enough people with triskaidekaphobia for them to also avoid the number 13 and numbering goes from 12 to 15. Sep 4, 2017 at 14:54
• @JonHanna - You’re right. The K Hotel Dunnan in Taipei lacks both a 13th and a 4th floor, since the hotel must cater to tourists from Japan, China, the US, and so forth. I suspect many other hotels in Taipei are the same (I only stayed at the one). Sep 4, 2017 at 16:28
• @Obie2.0 Did they have a 14th? Generally the digit is skipped rather than the number, so somewhere I once stayed in Vancouver (an area where both Asian fear of four and European fear of 13 can be found) had 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 15, 16… Some large buildings even have …38, 39, 50, 51…. Sep 4, 2017 at 16:36

According to the Wikipedia page for Japanese superstitions, in Japanese culture, the number 4 is an unlucky number because it is sometimes pronounced shi, which means death.

Also, in the Wikipedia page for Tetraphobia (the fear of the number 4):

The Chinese word for four (四, pinyin: sì, jyutping: sei3), sounds quite similar to the word for death (死, pinyin: sǐ, jyutping: sei2), in many varieties of Chinese. Similarly, the Sino-Japanese, Sino-Korean, and Sino-Vietnamese words for four, shi (し, Japanese), and sa (사, Korean), sound similar or identical to death in each language (see Korean numerals, Japanese numerals, Vietnamese numerals).

Essentially, the number 4, thanks to how it can be pronounced, is associated with death in a lot of East-Asian countries, particularly Japan, which is where the manga, Death Note, and the anime in question are produced. As the name of the manga/anime implies, death is one of the main themes in the story. It is thematically appropriate that the numeric references made in the Death Note hold this cultural significance and association with death.

• Ah, I see you quickly came to the same conclusion yourself. Nevermind. ;)
– Walt
Sep 4, 2017 at 12:03
• @Walt I had an idea that 4 was associated with death before re-watching the anime, recently, and picked up on the pattern - I just didn't know if it was, indeed, merely a coincidence, or an actual superstition and what it means, etc. Sep 4, 2017 at 12:14